Flamingo Color

To examine this hypothesis, the researchers studied seasonal variations in flamingo color at three wetlands in Spain. The team also monitored the birds' breeding, feather maintenance, and courtship activities.

Using telescopes, the scientists assigned each flamingo a color value based on a scale of one to three, ranging from very pale to vibrant pink.

The team found that the color values dropped from an average of 1.7 in February—the height of the mating season—to an average of 1.0 in May, June, July, August, and September, when the birds were looking after hatchlings. In October the values leapt up again, to 1.6.

Flamingos, like all birds, produce oil in glands near their tails. Birds daub this oil onto their feathers with their beaks.

The oil is well known to improve the longevity of feathers and keep them waterproof. But Amat suspected that the flamingos might also be using the substance for coloration.